“The Egyptian people will never forget the historic positions of late King Abdullah bin Abdulaziz toward Egypt and its people,” President Abdel Fattah Al-Sisi expressed his condolences to the late King Abdullah bin Abdulaziz Al-Saud.

World leaders sent expressive condolences following the death of the Saudi king on Friday morning, but few among them owe so much to the royal’s relationship as Egypt.

Calling for an unprecedented seven days of national mourning for King Abdullah, Al-Sisi’s office continued: “History will never forget his numerous achievements in the defence of Arabism and Islam; acts which he performed with honour, honesty and sincerity, guided by truth, justice, chivalry and courage.”

After the overthrow of Muslim Brotherhood-affiliated president Mohamed Morsi, Egypt’s tumultuous economy was kept afloat with billions of dollars of Gulf support, with Saudi Arabia the chief player leading the rally.

The kingdom pledged $5bn in cash, deposits and oil products days after the Egyptian army returned to power in July 2013. Then, following Al-Sisi’s presidential victory, assembled a conference of donor countries to finance over $60bn worth of projects in Egypt.

And the support was more than financial. Two days after the bloody clearances of pro-Muslim Brotherhood sit-ins in August 2013 when over 600 protesters were killed, and possibly hundreds more, by the security forces, King Abdullah came to the defence of Egypt’s military leadership and said: “The Kingdom of Saudi Arabia, its people and government stood and stands by today with its brothers in Egypt against terrorism.”

“I call on the honest men of Egypt and the Arab and Muslim nations … to stand as one man and with one heart in the face of attempts to destabilise a country that is at the forefront of Arab and Muslim history,” he continued.

King Abdullah’s next in line, Prince Salman, has vowed to carry on the same approach as his predecessor.

Seemingly to dispel any doubt that relations with Saudi Arabia and its dollars could be changed following Abdullah’s death, Al-Sisi’s statement continued to express his “full confidence” that Prince Salman “will continue the late King’s legacy to serve the causes of the Arab and Islamic nations”.

“There will be continuity more than reform,” agrees Amr Adly, a non-resident scholar at the Carnegie Middle East Center. Continued support should not be in doubt, Adly told Daily News Egypt.

“In recent times King Abdullah was out of the loop in decision making, the shots were being called from behind him. The policy vis-à-vis Egypt is part of a comprehensive strategy across the region encompassing Syria, containing Iran and so on. Despite Prince Salman taking the throne, it is the same group of royals dictating foreign policy.”

The idea of one individual king monarch calling the shots is a mistake according to Adly, in fact there is a strong informal institution of diplomacy and negotiation between the many Saudi royals in terms of policy making.

Saudi Arabia was tightly allied with former president Hosni Mubarak but after his deposition in 2011 the rise of the Muslim Brotherhood was a source of severe concern. Riyadh has spent billions of dollars containing movements such as the Brotherhood across the region that it sees as a threat to its institutional and religious authority.

“Saudi influence in the region suffered in the past three or four years following the Arab Spring and advancement in other brands of political Islam, for a moment it looked like the Muslim Brotherhood’s form would take over from the monarchy-based Islam of Saudi Arabia,” Amr Adly told Daily News Egypt.

“The Saudis fought back, they were desperate to maintain a friendly political system in Egypt, they saw disabling the Brotherhood in Egypt as key to their regional strategy.”

But other international movements now pose a challenge to Gulf power. International crude oil prices have been at a five-year low and fell almost 50% last year as the United States pumped at its fastest rate in three decades.

Saudi Arabia, the biggest producer in the Organisation of Petroleum Exporting Countries (OPEC), has not responded by reducing output supply, as a way of preserving their share of the market, despite a significant fall in revenues for an industry that accounts for 46% of its GDP.

The Saudi government’s own projections expect the national budget deficit to almost triple from 2014 to 145bn riyals ($39bn) this year and have announced that they will borrow and use financial reserves to plug the gap.

With a global power that comes through oil and finance, falling oil revenue for Saudi Arabia will no doubt pose a challenge in Riyadh being able to support the brands of governance and Islam it desires across the Middle East.

“The Saudi attitude will not change, it is desperate to maintain a friendly political system in Egypt,” Amr Adly continued, but he sees the future as uncertain. “The question is in what form and extent will the support continue, they are not willing to continue providing the vast financial support to Egypt indefinitely. Ultimately, right now oil revenues may not be the most important factor influencing relations with Egypt, but we don’t know how long this will last.”